It’s the largest lake in the state — for now. But California’s Salton Sea, just northeast of San Diego, is shrinking rapidly, and a recent California Supreme Court ruling threatens to exacerbate its decline. In March, the California court upheld a massive water-transfer system, agreed upon in 2003, that diverts billions of gallons of water from Imperial Valley farmland in Southern California to residents of San Diego County. The plan, known as the Quantification Settlement Agreement, is “the largest agriculture-to-urban water transfer in the history of the United States,” according to NPR. It will also cut off the agricultural runoff that replenishes the Salton Sea, and could cause the lake to dry up entirely in a matter of years.

With a depth of 52 ft. (16 m), the Salton Sea is not terribly deep, and is reportedly losing almost a foot each year. Initially created by a massive Colorado River flood in the early 1900s, it was a remarkable oddity — an oasis in the middle of the desert — and home to a popular resort town. But by the 1970s, that all changed: the sea’s rising salinity began to kill off its aquatic life. (According to a University of California at Davis study published in 2009, the sea contains about 44 grams of salt for every liter, about nine more grams than the Pacific Ocean.) With dead fish washing ashore, the celebrities and tourists largely stopped coming, and Salton City became little more than a ghost town.

The continued drying-out of the Salton Sea poses a significant ecological problem: its 376 sq. mi. (974 sq km) of seabed has absorbed decades of toxic agricultural pollutants from nearby farms, according to the NPR report. With the loss of water, the sea’s salt content causes the material to become airborne with just a slight breeze, creating wind storms and reducing air quality.

There are potential wildlife risks as well. According to the Audubon Society, more than 400 different migratory bird species stop over at the Salton Sea each year, including the American white pelican. If the sea goes away, the group says, that could lead to massive die-offs and even extinctions.

The Aral Sea, which lies between Kazakhstan and Uzbekistan, serves as a potent reminder of how badly things could go for the Salton. Steadily shrinking after the 1960s, it dropped to 10% of its original size in 2007. The local fishing industry has been destroyed, and the newly exposed seabed pollution has caused serious health problems in neighboring communities. With little action, California could very well have its own Aral Sea in a few years.

Erica Ho was previously a reporter for TIME in Hong Kong where she wrote about technology, pop culture and Asian international affairs. Before that, she worked at Gizmodo, Lifehacker and AOL. She now currently runs Map Happy, a travel-oriented site.